La dynamique des coordinations inter-segmentaires, résultat d'une coalition des contraintes neuromusculaires et spatiales

  • Salesse Robin

  • Isodirectionality Principle
  • Muscular Homology Principle
  • Plane of Motion
  • Symmetry

THESE

This Thesis presents the results of five experiments carried out to investigate the role of neuromuscular constraints, spatial constraints, visual feedback and plane of motion, on interlimb coordination dynamics (bimanual, hand-foot, handheld pendulum). In particular, we investigated the conditions under which these constraints influence pattern stability and changes. Specifically, we assessed (1) the nature of the interaction between neuromuscular and directional constraints as a function of the plane of motion of the task are performed and (2) the role of visual perception as a support of the directional constraint. Pattern stability (phase transitions, time to transition, and relative phase variability) and accuracy of performance (absolute error of the relative phase) were analyzed. Results show that whatever the experimental task context, directional constraints play a dominant role in interlimb coordination dynamics. Indeed, symmetrical movements with respect to the sagittal plane of the body exhibit the most stable and accurate patterns of coordination, irrespective of the plane of motion in which the tasks are performed. However, neuromuscular constraints also play a secondary role. Manipulation of the visual information about the relative direction of movement shows that a “perceptual isodirectional principle” is at work during the production of interlimb coordination. However, the influence of this principle depends on the conditions in which the tasks are performed (plane of motion, neuromuscular coupling). To sum up, the present work suggests that interlimb coordination dynamics is a result of complex interaction, in cooperation or in competition, between constraints of various origins.